The invention relates to a trailer coupling including a ball neck, which is movable between an operative position and a rest position and which has a pivot bearing body arranged at a first end and a coupling ball arranged at a second end, a pivot bearing unit, which is arranged fixed to the vehicle and by means of which the pivot bearing body is received such that it is pivotal about the pivot axis between the operative position and the rest position, and a rotation blocking arrangement having at least two rotation blocking bodies, which are guided by means of a guide body to be movable in a guide direction having at least one component in the radial direction relative to the pivot axis, wherein, in the operative position, the rotation blocking bodies are movable into a rotation blocking position by a movement in the guide direction and, in this rotation blocking position, engage with a receptacle in the pivot bearing body in order to block a pivotal movement of the pivot bearing body about the pivot axis relative to the guide body, and are movable into a release position and, in this release position, are not in engagement with the respective receptacle, and having an actuating body which has a respective cam face, that runs transversely to the guide direction, for each of the rotation blocking bodies and which is arranged to be rotatable about the pivot axis and as a result of the rotary movement whereof in a direction of actuation the at least two rotation blocking bodies are movable and urgeable in the guide direction.
Trailer couplings of this kind are known for example from EP 1 741 572 A1.
However, in trailer couplings of this kind a fundamental problem is to make them as compact and as structurally simple as possible so that they can also be used in restricted spatial conditions.